1. Field of the Invention
The present invention relates to a CAD system with a dimension-line editing function for editing drawing data corresponding to a given dimension line, and particularly, to a computer aided design (CAD) system with a dimension-line editing function for efficiently editing drawing data involving many dimension lines.
2. Description of the Related Art
Computer aided design (CAD) systems are employed to edit machine drawings, etc. The CAD systems display drawings that involve dimension lines, and users interactively enter data for editing the dimension lines. According to the entered data, the CAD systems process the drawing. The CAD systems must efficiently edit and process drawing data even if the data involve many dimension lines.
To edit a drawing according to the dimension lines thereof with a conventional CAD system, a user must specify an objective dimension line, an endpoint of the dimension line to edit, and the target length of the dimension line. According to these data, the CAD system processes drawing data corresponding to the objective dimension line. Since the conventional CAD system asks a user to specify objective dimension lines one by one, it takes a long time to edit a drawing if it involves many dimension lines.
Another conventional CAD system asks a user to enter the numeric relationships between dimension lines that are in parallel with one another in a drawing, an endpoint of a reference dimension line to be edited, and a target length for the reference dimension line. According to these data, the CAD system calculates target lengths of the parallel dimension lines, and according to the results of the calculations, edits drawing data corresponding to the endpoints of these dimension lines. Although the user is not asked to specify the dimension lines one by one, the user must register the numeric relationships between the dimension lines. This results in increasing the editing time for the drawing.
In any conventional CAD system, a user must always specify an endpoint to edit an objective dimension line.